To allow the httpd service to run on the 8001 tcp port (-a for add), type:

# semanage port -a -t http_port_t -p tcp 8001

Note1: Use the -d option instead of the -a option to remove a port from the list.
Note2: In case the 8001tcp port is already assigned to an other service, use the -m option (see Sander van Vugt RHCE FAQ for more information): a port can only be used by one service at a time.

Additional specific service configuration

In addition to the SELinux policy change, you may need to adjust the service configuration.
For example, with the httpd service, you will need to update the Listen directive or, if it’s a virtual host, the <VirtualHost> directive in the /etc/httpd/conf/httpd.conf file to take into account the new port.